The raid came after officers posing as customers arrested five drivers offering their services through a mobile app, in an operation aimed at combating illegal taxis.

The five men were suspected of illegally carrying passengers and driving without insurance and are being held for further investigation, police said in a statement.

Police did not name Uber Technologies but local Cable TV news showed officers taking away computers and documents from the company's Hong Kong office, which opened in July last year.

It's the latest setback for the San Francisco-based company as its overseas expansion meets multiple legal and regulatory challenges.

Uber has also faced other challenges in greater China, where police this year paid visits to its offices in the mainland cities of Chengdu and Guangzhou as part of a widening investigation into its operations.

In a statement, Uber spokesman Harold Li said it "ensures that all rides are covered by insurance, and all drivers on the platform undergo an extensive background check."

The company said it stands by its drivers "100 percent" and welcomed the opportunity to work with the authorities on updating regulations.